package lanqiao;

// 递归dfs  重复 变化 边界
public class l2013_03 {
    public static void main(String arg[]){
        int ans = f(0,0);
        System.out.println(ans);
    }

    private static int f(int i,int j){
        if (i == 3 || j==4)
            return 1;
        return f(i+1,j) + f(i,j+1);
    }
}
